Production Client ID/Secret not generating - Internal Server Error on Regenerate

Description
I'm building CallALink, a User-managed OAuth app that lets users connect their own Zoom account so CallALink can create/delete Zoom meetings on their behalf via the API (meeting:write:meeting, meeting:delete:meeting scopes). Development works correctly end-to-end. On the Production tab, App Credentials shows both Client ID and Client Secret completely blank, and clicking Regenerate on Client Secret fails every time. This is blocking Scopes/OAuth URL generation and Publish for Production.

How To Reproduce
1. Authentication method / app type: OAuth, User-managed app
2. Go to app → Production tab → Basic Information → App Credentials
3. Client ID and Client Secret fields are both empty (Development has valid values, Production does not)
4. Click "Regenerate" next to Client Secret
5. Error: "Internal Server Error" toast appears

Already tried: refreshing and retrying, incognito window, a different browser entirely — same failure every time.

App name: CallALink